try:
 try_suite
except Exception1,Exception2,...,Argument:
 exception_suite
...... #other exception block
else:
 no_exceptions_detected_suite
finally:
 always_execute_suite

try:
 try_suite
except:
 exception block
　　

try:
 try_suite
except Exception:
 exception block
 

>>> try:
...  res = 2/0
... except ZeroDivisionError:
...  print "Error:Divisor must not be zero!"
... 
Error:Divisor must not be zero!

try:
 floatnum = float(raw_input("Please input a float:"))
 intnum = int(floatnum)
 print 100/intnum
except ZeroDivisionError:
 print "Error:you must input a float num which is large or equal then 1!"
except ValueError:
 print "Error:you must input a float num!"

[root@Cherish tmp]# python test.py 
Please input a float:fjia
Error:you must input a float num!
[root@Cherish tmp]# python test.py 
Please input a float:0.9999
Error:you must input a float num which is large or equal then 1!
[root@Cherish tmp]# python test.py 
Please input a float:25.091
4

>>> try:
...  1/0
... except ZeroDivisionError,reason:
...  pass
... 
>>> type(reason)
<type 'exceptions.ZeroDivisionError'>
>>> print reason
integer division or modulo by zero
>>> reason
ZeroDivisionError('integer division or modulo by zero',)
>>> reason.__class__
<type 'exceptions.ZeroDivisionError'>
>>> reason.__class__.__doc__
'Second argument to a division or modulo operation was zero.'
>>> reason.__class__.__name__
'ZeroDivisionError'

>>> import syslog
>>> try:
...  f = open("/root/test.py")
... except IOError,e:
...  syslog.syslog(syslog.LOG_ERR,"%s"%e)
... else:
...  syslog.syslog(syslog.LOG_INFO,"no exception caught\n")
... 
>>> f.close()

>>> import syslog
>>> try:
...  f = open("/root/test.py")
... except IOError,e:
...  syslog.syslog(syslog.LOG_ERR,"%s"%e)
... else:
...  syslog.syslog(syslog.LOG_INFO,"no exception caught\n")
... finally: 
>>>  f.close()

>>> assert len('love') == len('like')
>>> assert 1==1
>>> assert 1==2,"1 is not equal 2!"
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
AssertionError: 1 is not equal 2!

>>> try:
...   assert 1 == 2 , "1 is not equal 2!"
... except AssertionError,reason:
...   print "%s:%s"%(reason.__class__.__name__,reason)
... 
AssertionError:1 is not equal 2!
>>> type(reason)
<type 'exceptions.AssertionError'>

>>> with open('/root/test.py') as f: 
...   for line in f: 
...     print line 

>>> raise NameError
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
NameError
>>> raise NameError() #异常类的实例
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
NameError
>>> raise NameError,("There is a name error","in test.py")
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
>>> raise NameError("There is a name error","in test.py") #注意跟上面一个例子的区别
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
NameError: ('There is a name error', 'in test.py')
>>> raise NameError,NameError("There is a name error","in test.py") #注意跟上面一个例子的区别
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
NameError: ('There is a name error', 'in test.py')

>>> try:
...   1/0
... except:
...   import sys
...   tuple = sys.exc_info()
... 
>>> print tuple
(<type 'exceptions.ZeroDivisionError'>, ZeroDivisionError('integer division or modulo by zero',), <traceback object at 0x7f538a318b48>)
>>> for i in tuple:
...   print i
... 
<type 'exceptions.ZeroDivisionError'> #异常类    
integer division or modulo by zero #异常类的实例
<traceback object at 0x7f538a318b48> #跟踪记录对象